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Abstract:

A management system includes: plural management apparatuses each of which
includes a first transmitting unit that, when processing devices
connected to a communication unit are searched with reference to a first
management table in which information of a processing device managed by
the management apparatus is registered and a processing device which is
not managed by the management apparatus is detected, transmits detection
information of the processing device to the communication unit, and a
first registration unit, when a processing device management request
corresponding to the detection information of the processing device is
received from the communication unit, registers information of the
processing device related to the processing device management request in
the first management table; and an information management server
including a change unit that changes information of the management
apparatus and a second transmitting unit that transmits the processing
device management request to the communication unit.

Claims:

1. A management system comprising: a plurality of management apparatuses
each of which includes a first transmitting unit that, when processing
devices connected to a communication unit are searched with reference to
a first management table in which information of a processing device
managed by the management apparatus is registered and a processing device
which is not managed by the management apparatus is detected, transmits
detection information of the processing device to the communication unit,
and a first registration unit that, when a processing device management
request corresponding to the detection information of the processing
device is received from the communication unit, registers information of
the processing device related to the processing device management request
in the first management table; and an information management server that
includes a change unit and a second transmitting unit, wherein, in the
information management server, when information of the processing device
related to the detection information of the processing device received
from the communication unit is registered in a second management table in
which the information of the processing device and information of the
management apparatus managing the processing device are associated with
each other, the change unit changes the information of the management
apparatus associated with the information of the processing device which
is related to the detection information of the processing device in the
second management table to the information of the management apparatus
transmitting the detection information of the processing device, and when
the information of the processing device related to the detection
information of the processing device received from the communication unit
is registered in the second management table, the second transmitting
unit transmits the processing device management request to the
communication unit.

2. The management system according to claim 1, wherein, in the
information management server, when the information of the management
apparatus associated with the processing device is changed in the second
management table, the second transmitting unit transmits changed
information to the management apparatus related to the information of the
management apparatus before the change, and the management apparatus
further includes a deleting unit that deletes the information of the
processing device related to the changed information from the first
management table when the changed information is received from the
communication unit.

3. The management system according to claim 1, wherein, when
communication with the processing device registered in the first
management table is unavailable, the first transmitting unit transmits
communication unavailable information of the processing device to the
communication unit, the information management server further includes a
second registration unit that registers the communication unavailable
information in the second management table so as to be associated with
the information of the processing device when the communication
unavailable information of the processing device is received from the
communication unit, and the change unit searches for the information of
the processing device associated with the communication unavailable
information prior to the information of other processing devices which
are not associated with the communication unavailable information in the
second management table, and detects the information of the processing
device related to the detection information of the processing device from
the information of the processing devices registered in the second
management table.

4. The management system according to claim 2, wherein, when
communication with the processing device registered in the first
management table is unavailable, the first transmitting unit transmits
communication unavailable information of the processing device to the
communication unit, the information management server further includes a
second registration unit that registers the communication unavailable
information in the second management table so as to be associated with
the information of the processing device when the communication
unavailable information of the processing device is received from the
communication unit, and the change unit searches for the information of
the processing device associated with the communication unavailable
information prior to the information of other processing devices which
are not associated with the communication unavailable information in the
second management table, and detects the information of the processing
device related to the detection information of the processing device from
the information of the processing devices registered in the second
management table.

5. The management system according to claim 1, wherein the change unit
completes a change in the information of the management apparatus after
the first registration unit registers the information of the processing
device in the first management table.

6. The management system according to claim 2, wherein the change unit
completes a change in the information of the management apparatus after
the first registration unit registers the information of the processing
device in the first management table.

7. The management system according to claim 3, wherein the change unit
completes a change in the information of the management apparatus after
the first registration unit registers the information of the processing
device in the first management table.

8. The management system according to claim 4, wherein the change unit
completes a change in the information of the management apparatus after
the first registration unit registers the information of the processing
device in the first management table.

9. A management apparatus comprising: a transmitting unit that, when
processing devices connected to a communication unit are searched with
reference to a management table in which information of a processing
device managed by the management apparatus is registered and a processing
device which is not managed by the management apparatus is detected,
transmits detection information of the processing device to an
information management server through the communication unit; and a
registration unit that, when a processing device management request
corresponding to the detection information of the processing device is
received from the communication unit, registers information of the
processing device related to the processing device management request in
the first management table.

10. A management method comprising: transmitting detection information of
a processing device which is not managed by a management apparatus to an
information management server through a communication unit when
processing devices connected to the communication unit are searched with
reference to a management table in which information of a processing
device managed by the management apparatus is registered and the
processing device which is not managed by the management apparatus is
detected; and registering information of the processing device related to
a processing device management request in the first management table when
the processing device management request corresponding to the detection
information of the processing device is received from the communication
unit.

11. A non-transitory computer readable medium storing a control program
that causes a computer to perform: transmitting detection information of
a processing device which is not managed by a management apparatus to an
information management server through a communication unit when
processing devices connected to the communication unit are searched with
reference to a management table in which information of a processing
device managed by the management apparatus is registered and the
processing device which is not managed by the management apparatus is
detected; and registering information of the processing device related to
a processing device management request in the first management table when
the processing device management request corresponding to the detection
information of the processing device is received from the communication
unit.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on and claims priority under 35 USC 119
from Japanese Patent Application No. 2011-067225 filed Mar. 25, 2011.

BACKGROUND

Technical Field

[0002] The present invention relates to a management system, a management
apparatus, a management method, and a non-transitory computer readable
medium storing a control program.

SUMMARY

[0003] According to an aspect of the invention, there is provided a
management system including: plural management apparatuses each of which
includes a first transmitting unit that, when processing devices
connected to a communication unit are searched with reference to a first
management table in which information of a processing device managed by
the management apparatus is registered and a processing device which is
not managed by the management apparatus is detected, transmits detection
information of the processing device to the communication unit, and a
first registration unit that, when a processing device management request
corresponding to the detection information of the processing device is
received from the communication unit, registers information of the
processing device related to the processing device management request in
the first management table; and an information management server that
includes a change unit and a second transmitting unit, wherein, in the
information management server, when information of the processing device
related to the detection information of the processing device received
from the communication unit is registered in a second management table in
which the information of the processing device and information of the
management apparatus managing the processing device are associated with
each other, the change unit changes the information of the management
apparatus associated with the information of the processing device which
is related to the detection information of the processing device in the
second management table to the information of the management apparatus
transmitting the detection information of the processing device, and when
the information of the processing device related to the detection
information of the processing device received from the communication unit
is registered in the second management table, the second transmitting
unit transmits the processing device management request to the
communication unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Exemplary embodiments of the present invention will be described in
detail based on the following figures, wherein:

[0005] FIG. 1 is a block diagram illustrating an example of the structure
of a management system according to an exemplary embodiment;

[0006]FIG. 2 is a block diagram illustrating an example of the structure
of a management apparatus;

[0007]FIG. 3 is a block diagram illustrating an example of a management
center server;

[0008]FIG. 4 is a diagram illustrating an example of a communication
sequence performed between the management apparatus and the management
center server when the management apparatus detects a new device;

[0009] FIG. 5 is a diagram illustrating an example of a communication
sequence performed between the management apparatus and the management
center server when the management apparatus detects a new device;

[0010] FIG. 6 is a diagram illustrating an example of a communication
sequence performed between the management apparatus and the management
center server when the management apparatus cannot detect a target
device;

[0011]FIG. 7 is a diagram illustrating an example of a management
apparatus information management table;

[0012]FIG. 8 is a diagram illustrating an example of a device information
management table;

[0013]FIG. 9 is a diagram illustrating an example of a device management
table;

[0014] FIG. 10 is a diagram illustrating an example in which a device A
connected to a first sub-net which is managed by a first management
apparatus is moved to a second sub-net managed by a second management
apparatus;

[0015] FIG. 11 is a diagram illustrating an example in which the device B
connected to the second sub-net which is managed by the second management
apparatus is replaced with the device A connected to the first sub-net
managed by the first management apparatus; and

[0016] FIG. 12 is a diagram illustrating an example in which the device A
in the first sub-net managed by the first management apparatus is
exchanged with the device B in the second sub-net managed by the second
management apparatus.

DETAILED DESCRIPTION

[0017] An exemplary embodiment relates to a management system.

[0018] FIG. 1 shows an example of the structure of a management system 1.

[0019] As shown in FIG. 1, in the management system 1, a management center
server 10 is connected to plural sub-nets 201, 202, . . . ,
20N-1, and 20N (N is an arbitrary integer), which are
management targets, through a communication unit 100, such as a LAN
(Local Area Network) or an Internet communication line.

[0021] The management apparatuses 301 to 30N manage various
kinds of devices (processing devices), such as the image forming devices
211 to 21N and the personal computers 221 to 22N in
the sub-nets 201 to 20N, which are management targets, through
the communication units 231, 232, . . . , 23N-1, and
23N, such as LANs (Local Area Networks), according to a
communication protocol, such as an SNMP (Simple Network Management
Protocol), respectively.

[0022] The management apparatuses 301 to 30N register and store
the IP address (Internet Protocol Addresses) of each device in a table,
periodically collect the information of each device through the
communication units 231 to 23N, detect the state of each
device, and notify the state of each device to the management center
server 10, if necessary. In addition, the management apparatuses 301
to 30N manage the history information of each device. When a
specific event is detected, the management apparatuses 301 to
30N determine whether to notify the detection of the specific event
to the management center server 10 on the basis of the history. For
example, each of the management apparatuses 301 to 30N may
register a predetermined number of devices, for example, 100 devices and
manage the devices.

[0023] For convenience of explanation, the communication units are divided
into the communication unit 100 and the communication units 231,
232, . . . , 23N-1, and 23N. However, the same
communication unit may be used.

[0024] The image forming devices or the personal computers are given as
examples of the devices managed by the management apparatuses 301 to
30N, but the invention is not limited thereto. In addition, each of
the management apparatuses 301 to 30N may manage different
combinations of the devices. That is, any devices may be applied to this
exemplary embodiment as long as they have a structure managed by the
management apparatuses 301 to 30N.

[0025] The management center server 10 manages each device in the sub-nets
201 to 20N through the management apparatuses 301 to
30N.

[0026] For example, the management system 1 may be constructed such that
the sub-nets 201 to 20N are customers and the management center
server 10 is an administrator and the administrator may provide, for
example, business, maintenance, and logistics services. In this case, for
example, each of the sub-nets 201 to 20N is constructed in a
customer intranet and the management apparatuses 301 to 30N
manage the sub-nets 201 to 20N in the intranet.

[0027] In this example, for example, each of the management apparatuses
301 to 30N performs various kinds of management operations,
such as a failure state management operation, a printout management
operation, and a supply management operation, on each device in the
sub-nets 201 to 20N and transmits the management information to
the management center server 10. The management center server 10 searches
for an operator (for example, a customer engineer) for repairing the
failure of the device on the basis of the management information
transmitted to the management center server 10.

[0028] In the management system 1 having the above-mentioned structure,
the management apparatus 30 (arbitrary management apparatus) periodically
acquires information from the device in the sub-net 20, which is a
management target, detects the state of the device, periodically searches
for the sub-net 20, which is a management target, and determines whether
the IP address of the registered device is changed.

[0029] By the way, the operator determines whether to set the device as a
management target and registers the device in the management center
server 10. However, when the IP address of the registered device is
changed by a customer and the device is moved to a sub-net (a sub-net
managed by another management apparatus) other than the management target
after the registration, the management apparatus 30 cannot collect
information from the device since the device is not in the sub-net 20,
which is a management target. In addition, the management apparatus 30
cannot detect the device even when it periodically searches for the
sub-net 20, which is a management target. For example, the device may be
moved between the sub-nets by a change in physical connection in addition
to the change in the IP address.

[0030] In addition, since the setting of the device moved to the sub-net,
other than a management target, is changed only by the operator, labor
costs are generated or it takes time to recover a failure. Therefore, it
is difficult to provide a management service for the device (for example,
the dispatch of the operator due to a failure) during the recovery.

[0031] A technique is also considered in which, when the management
apparatus searches for the sub-net, which is a management target, and
detects the device whose IP address is changed, the IP address setting
registration information of the device is changed. As described above,
when the device is moved to a sub-net other than the management target,
the management apparatus cannot detect the device from the sub-net
managed by the management apparatus even though this technique is
applied.

[0032] For example, even when the technique disclosed in JP-A-2007-206998,
in which notification of error information is provided when the same
segment is searched and it is difficult to detect a device, is applied,
it is difficult to perform other recovery processes.

[0033] In contrast, in this exemplary embodiment, the following structure
and process make it possible to continuously manage the device moved
between the sub-nets.

[0034]FIG. 2 shows an example of the structure of each of the management
apparatuses 301 to 30N.

[0035] As shown in FIG. 2, each of the management apparatuses 301 to
30N includes a CPU (Central Processing Unit) 31, a storage unit 32
that stores, for example, programs (hereinafter, referred to as a program
storage unit 32), a temporary storage unit 33, a device search unit 34, a
table management unit 35, and a communication processing unit
(notification and request issuing unit) 36.

[0036] The program storage unit 32 is a storage unit capable of storing
data even when the power is turned off. The program storage unit 32
stores, for example, a program 32a or fixed data used by the CPU to
perform various kinds of processes. An exemplary example of the program
storage unit 32 is a ROM (Read-Only Memory). In addition, the program
storage unit 32 may be a non-volatile storage unit, such as an EEPROM
(Electrically Erasable Programmable Read-Only Memory), but the invention
is not limited thereto.

[0037] The program 32a may be stored in the program storage unit 32 before
the shipment of the management apparatus or it may be read from a
recording medium, such as a CD-ROM, by the operation of the user and then
stored in the program storage unit 32 after the shipment of the
management apparatus.

[0038] The temporary storage unit 33 is a data writable storage unit that
temporarily stores data. An exemplary example of the temporary storage
unit 33 is a RAM (Random Access Memory), but the temporary storage unit
33 is not limited thereto.

[0039] The temporary storage unit 33 stores a management apparatus
information management table 33a and a device information management
table 33b. The management apparatus information management table 33a and
the device information management table 33b may be stored in a
non-volatile storage unit, such as an EEPROM, but the invention is not
limited thereto.

[0040] Each of the management apparatuses 301 to 30N may store
the management apparatus information management table 33a and the device
information management table 33b in a single external storage device (for
example, a server) or plural external storage devices (for example,
servers) corresponding to the tables.

[0041] The CPU 31 reads, for example, the program 32a from the program
storage unit 32 to the temporary storage unit 33 and performs various
kinds of processes, if necessary.

[0042] The content of the processes of the device search unit 34, the
table management unit 35, and the communication processing unit 36 will
be described below. The device search unit 34, the table management unit
35, and the communication processing unit 36 may be implemented as the
functions of the CPU by the operation of the CPU.

[0043]FIG. 3 shows an example of the structure of the management center
server 10.

[0044] As shown in FIG. 3, the management center server 10 includes a CPU
11, a storage unit 12 that stores, for example, programs (hereinafter,
referred to as a program storage unit 12), a temporary storage unit 13, a
table management unit 14, and a communication processing unit (request
issuing unit) 15.

[0045] The program storage unit 12 is a storage unit capable of storing
data even when power is turned off. The program storage unit 12 stores,
for example, a program 12a or fixed data used by the CPU 11 to perform
various kinds of processes. An exemplary example of the program storage
unit 12 is a ROM. In addition, the program storage unit 12 may be a
non-volatile storage unit, such as an EEPROM, but the invention is not
limited thereto.

[0046] The program 12a may be stored in the program storage unit 12 before
the shipment of the management apparatus or it may be read from a
recording medium, such as a CD-ROM, by the operation of the user and then
stored in the program storage unit 12 after the shipment of the
management apparatus.

[0047] The temporary storage unit 13 is a data writable storage unit that
temporarily stores data. An exemplary example of the temporary storage
unit 13 is a RAM, but the temporary storage unit 13 is not limited
thereto.

[0048] The temporary storage unit 13 stores a device management table 13a.
The device management table 13a may be stored in a non-volatile storage
unit, such as an EEPROM, but the invention is not limited thereto.

[0050] The CPU 11 reads, for example, the program 12a from the program
storage unit 12 to the temporary storage unit 13 and performs various
kinds of processes, if necessary.

[0051] The content of the processes of the table management unit 14 and
the communication processing unit 15 will be described below. The table
management unit 14 and the communication processing unit 15 may be
implemented as the functions of the CPU 11 by the operation of the CPU
11.

[0052] Next, the content of the process of each unit of an N-th management
apparatus (arbitrary management apparatus) 30N and the management
center server 10 will be described with reference to FIGS. 4 to 6.

[0053] FIGS. 4 to 6 show a communication sequence between the N-th
management apparatus 30N and the management center server. FIG. 4
shows a communication sequence when the N-th management apparatus
30N (for example, the second management apparatus) detects a new
device. FIG. 5 shows a communication sequence when a device is moved from
the N-th management apparatus 30N (for example, the first management
apparatus). FIG. 6 shows a communication sequence when the N-th
management apparatus 30N (for example, the first management
apparatus) cannot detect a target device.

[0054] As shown in FIG. 4, in the communication sequence related to the
detection of a new device, first, the N-th management apparatus 30N
periodically (for example, at an interval of about 5 minutes) searches
for an N-th sub-net 20N, which is a management target, using the
device search unit 34 (Step S1). As a result of the search of the sub-net
by the device search unit 34, when the N-th management apparatus 30N
detects a new device X (for example, a new image forming device or a
personal computer) with reference to the device information management
table 33b, it transmits a device detection notice (information indicating
the detection of a processing device) to the management center server 10
using the communication processing unit 36 (Step S2). The device
detection notice includes the serial number of the N-th management
apparatus 30N and the serial number of the newly detected device.

[0056] As shown in FIG. 7, the management apparatus information management
table 33a includes the serial number of the management apparatus and the
information of the sub-net, which is a management target. The device
information management table 33b includes the IP address, serial number,
and state information of each device. For example, the device serial
number is a device model code and a device model number, but is not
limited thereto. Any information peculiar to the device may be used as
the device serial number.

[0057] The device search unit 34 detects a new device on the basis of the
device information management table 33b. That is, the device search unit
34 checks whether the serial number of each device in the N-th sub-net
20N is included in the device information management table 33b and
detects the device with a new device serial number as a new device.

[0058] The communication processing unit 36 adds the serial number of the
N-th management apparatus 30N and the serial number of the newly
detected device to the device detection notice with reference to the
management apparatus information management table 33a and the device
information management table 33b.

[0059] When receiving the device detection notice from the N-th management
apparatus 30N, the management center server 10 searches for the
information of the device X (the new device detected by the N-th
management apparatus 30N) related to the device detection notice in
the device management table 13a using the table management unit 14 (Step
S3). In this case, the table management unit 14 preferentially searches
for a device in a "missing" state in the device management table 13a. A
process of setting the state of the device to the "missing" state in the
device management table 13a is implemented by the communication sequence
shown in FIG. 6, which will be described below.

[0061] As shown in FIG. 9, the device management table 13a includes the IP
address, serial number, and state information of each device, the serial
number of the previous management apparatus, and the serial number of the
(current or latest) management apparatus.

[0062] When detecting the information of the device X from the device
management table 13a, the table management unit 14 remotely withdraws the
device X (Step S4). That is, the table management unit 14 changes the
state of the device X to a "non-installed" state in the device management
table 13a. In addition, the table management unit 14 copies the serial
number of the management apparatus to the serial number of the previous
management apparatus in the device management table 13a (Step S4).

[0063] The management center server 10 ends the process when it receives
the device detection notice, but cannot detect the information of the
device related to the device detection notice from the device management
table 13a, that is, when the device related to the device detection
notice is not managed by any management apparatus. The reason why this
process is performed is that, when the device related to the device
detection notice is not managed by any management apparatus, the operator
needs to determine the setting of the device.

[0064] Then, in the management center server 10, the communication
processing unit 36 responds to the device detection notice. That is, the
communication processing unit 36 returns a request to manage the device X
to the N-th management apparatus 30N in response to the device
detection notice indicating the detection of the information of the
device X from the device management table 13a (Step S5).

[0065] When receiving the request to manage the device X from the
management center server 10, the N-th management apparatus 30N
registers the device X in the device information management table 33b
using the table management unit 35 (Step S6). Specifically, the table
management unit 35 registers the IP address, serial number, and state
information of the device X in the device information management table
33b.

[0067] When receiving the request to install and register the device X
from the N-th management apparatus 30N, the management center server
10 changes the state of the device X to an "installed" state in the
device management table 13a using the table management unit 14 (Step S8).
In addition, the table management unit 14 registers the serial number of
the N-th management apparatus 30N as the serial number of the
management apparatus in the device management table 13a (Step S8).

[0068] As shown in FIG. 5, in the communication sequence related to, for
example, the movement of the device, first, the N-th management apparatus
30N periodically (for example, one polling operation a day) performs
polling using the communication processing unit 36 to check whether a
request is transmitted to the management center server 10 (Step S21).

[0069] In the management center server 10, the table management unit 14
searches whether the serial number of the N-th management apparatus
30N is registered as the serial number of the previous management
apparatus in the device management table 13a in response to the request
from the N-th management apparatus 30N (Step S22). The table
management unit 14 ends the process when the serial number of the N-th
management apparatus 30N is not registered as the serial number of
the previous management apparatus in the device management table 13a. In
addition, in the management center server 10, when the table management
unit 14 detects that the serial number of the N-th management apparatus
30N is registered as the serial number of the previous management
apparatus in the device management table 13a, the communication
processing unit 15 returns a request (changed information) to exclude the
device X related to the serial number of the previous management
apparatus from the management target to the N-th management apparatus
30N in response to the periodic polling (Step S23).

[0070] When receiving the request to exclude the device X from the
management target from the management center server 10, the N-th
management apparatus 30N deletes the information of the device X
from the device information management table 33b using the table
management unit 35 (Step S24).

[0071] As shown in FIG. 6, in the communication sequence related to the
detection of a target device, first, the N-th management apparatus
30N periodically (for example, at an interval of about 5 minutes)
searches for the N-th sub-net 20N, which is a management target,
using the device search unit 34 (Step S41). When the device search unit
34 cannot detect the device X as a result of the search of the sub-net,
the N-th management apparatus 30N transmits a device missing notice
(communication unavailable information) to the management center server
10 using the communication processing unit 36 (Steps S41 and S42). In
this case, the device missing notice includes the serial number of the
N-th management apparatus 30N and the serial number of the device X.
That is, the communication processing unit 36 adds the serial number of
the N-th management apparatus 30N and the serial number of the
detected device to the device missing notice with reference to the
management apparatus information management table 33a and the device
information management table 33b.

[0072] When the management center server 10 receives the device missing
notice from the N-th management apparatus 30N, the table management
unit 14 searches for the information of the device X from the device
management table 13a (Step S43). Then, the table management unit 14
changes the state of the device X to a "missing" state in the device
management table 13a.

[0073] Then, when the management center server 10 receives the device
detection notice related to the device X transmitted from another
management apparatus, the table management unit 14 searches for the
device in a "missing" state prior to the devices in the other states in
the device management table 13a. Then, the management center server 10
performs the same process as that shown in FIG. 4 when the information of
the device X is detected from the device management table 13a by the
search of the table management unit 14. That is, for example, when the
information of the device X is detected from the device management table
13a, the management center server 10 changes the state of the device X to
a "non-installed" state in the device management table 13a using the
table management unit 14 (for example, Step S4).

[0074] Next, the structure and process of the management apparatuses
301 to 30N and the management center server 10 will be
described with reference to examples shown in FIGS. 10 to 12.

[0075] (1) FIG. 10 shows an example in which a device A in the first
sub-net 201 managed by the first management apparatus 301
(arbitrary management apparatus) is moved to the second sub-net 202
managed by the second management apparatus 302 (another arbitrary
management apparatus).

[0076] In this case, the communication sequence related to the detection
of a device shown in FIG. 4 is performed between the second management
apparatus 302 and the management center server 10.

[0077] That is, in the second management apparatus 302, the device A
is registered in the device information management table 33b. In the
device management table 13a of the management center server 10, the state
of the device A is changed to a "non-installed" state and the serial
number of the first management apparatus 301 is registered as the
serial number of the previous management apparatus (the serial number of
the (current or latest) management apparatus is copied to the serial
number of the previous management apparatus). In the management center
server 10, at the time when the second management apparatus 302
registers the device A in the device information management table 33b,
the state of the device A is changed to an "installed" state in the
device management table 13a, that is, a change in the management state of
the device is completed, and the serial number of the second management
apparatus 302 is registered as the serial number of the management
apparatus in the device management table 13a.

[0078] As such, when a new device A is detected in the sub-net 201
managed by the second management apparatus 302, the second
management apparatus 302 registers the newly detected device A as a
management target in the management center server 10 (update of
registration) and manages the newly detected device A thereafter.

[0079] That is, when the newly detected device A, which is not a
management target, has already been registered in the management center
server 10, the second management apparatus 302 registers the device
A as a management target in the device information management table 33b.

[0080] In this way, the management system 1, the management center server
10, or the second management apparatus 302 is capable of
continuously managing the device moved between the sub-nets.

[0081] The communication sequence related to the deletion of device
information shown in FIG. 5 and the communication sequence related to the
missing of a device shown in FIG. 6 are performed between the first
management apparatus 301 and the management center server 10.

[0082] That is, when the management center server 10 detects the serial
number of the first management apparatus 301 from the serial number
of the management apparatus that has previously managed the device A in
the device management table 13a at the periodic polling time of the first
management apparatus 301, the first management apparatus 301
deletes the information of the device A from the device information
management table 33b in response to a request from the management center
server 10.

[0083] Since the first management apparatus 301 cannot detect the
device A in the first sub-net 201, which is a management target, the
management center server 10 changes the state of the device A to a
"missing" state in the device management table 13a.

[0084] Next, the relation between the communication sequences shown in
FIGS. 4 to 6 will be described. When the communication sequence shown in
FIG. 4 is not performed up to the last process, the communication
sequence shown in FIG. 5 is also not performed up to the last process.
That is, the communication sequence shown in FIG. 5 depends on the
communication sequence shown in FIG. 4. However, the communication
sequence shown in FIG. 6 does not depend on the communication sequences
shown in FIGS. 4 and 5. That is, the communication sequence shown in FIG.
4 may be performed after the communication sequence shown in FIG. 6,
depending on the execution timing of the first management apparatus
301.

[0085] In some cases, after the communication sequence shown in FIG. 6 is
performed and the management center server 10 changes the state of the
device A to a "missing" state in the device management table 13a, the
communication sequence shown in FIG. 4 is performed and the second
management apparatus 302 transmits the device detection notice
related to the device A to the management center server 10. Then, in the
management center server 10, the table management unit 14 searches for
the device in a "missing" state in the device management table 13a in
advance. Then, as a result of the search, when the information of the
device A is detected from the device management table 13a, the table
management unit 14 changes the state of the device A to a "non-installed"
state and registers the serial number of the first management apparatus
301 as the serial number of the previous management apparatus.

[0086] (2) FIG. 11 shows an example in which a device B in the second
sub-net 202 managed by the second management apparatus 302 is
replaced with the device A in the first sub-net 201 managed by the
first management apparatus 301. For example, the device A is moved
to the second sub-net 202, the IP address of the device B is set to
the device A, and the IP address of the device B is changed to a value
that cannot be searched by the second management apparatus 302.

[0087] In this case, the communication sequence related to the detection
of a device shown in FIG. 4, the communication sequence related to the
deletion of device information shown in FIG. 5, and the communication
sequence related to the missing of a device shown in FIG. 6 are performed
between the second management apparatus 302 and the management
center server 10.

[0088] That is, the second management apparatus 302 registers the
device A in the device information management table 33b. In the
communication sequence related to the detection of a device shown in FIG.
4, the second management apparatus 302 detects the device A as a new
device since the IP address of the device A is registered in the device
information management table 33b, but the serial number of the device A
is not identical to the serial number corresponding to the IP address.

[0089] In the device management table 13a of the management center server
10, the state of the device A is changed to a "non-installed" state and
the serial number of the first management apparatus 301 is
registered as the serial number of the previous management apparatus. In
the management center server 10, at the time when the second management
apparatus 302 registers the device A in the device information
management table 33b, the state of the device A is changed to an
"installed" state in the device management table 13a and the serial
number of the second management apparatus 302 is registered as the
serial number of the management apparatus in the device management table
13a.

[0090] Since the second management apparatus 302 cannot detect the
device B in the second sub-net 202, which is a management target,
the management center server 10 changes the state of the device B to a
"missing" state in the device management table 13a.

[0091] Since the management center server 10 cannot detect the serial
number of the second management apparatus 302 from the serial number
of the management apparatus that has previously managed the device B in
the device management table 13a even though periodic polling is
performed, the second management apparatus 302 ends the process
without deleting the information of the device B from the device
information management table 33b (while maintaining the information of
the device B in the device information management table 33b).

[0092] Similar to FIG. 10, the communication sequence related to the
deletion of device information shown in FIG. 5 and the communication
sequence related to the missing of a device shown in FIG. 6 are performed
between the first management apparatus 301 and the management center
server 10.

[0093] (3) FIG. 12 shows an example in which the device A in the first
sub-net 201 managed by the first management apparatus 301 is
exchanged with the device B in the second sub-net 202 managed by the
second management apparatus 302. In this example, the IP address of
the device A is reset to the IP address of the device B and the IP
address of the device B is reset to the original IP address of the device
A.

[0094] In this case, the communication sequence related to the detection
of a device shown in FIG. 4, the communication sequence related to the
deletion of device information shown in FIG. 5, and the communication
sequence related to the missing of a device shown in FIG. 6 are performed
between the first management apparatus 301 and the management center
server 10 and between the second management apparatus 302 and the
management center server 10.

[0095] That is, in the first management apparatus 301, the device B
is registered in the device information management table 33b. In the
device management table 13a of the management center server 10, the state
of the device B is changed to a "non-installed" state and the serial
number of the second management apparatus 302 is registered as the
serial number of the management apparatus in the previous management
process. In the management center server 10, at the time when the first
management apparatus 301 registers the device B in the device
information management table 33b, the state of the device B is changed to
an "installed" state in the device management table 13a and the serial
number of the first management apparatus 301 is registered as the
serial number of the management apparatus in the device management table
13a.

[0096] When the management center server 10 detects the serial number of
the first management apparatus 301 from the serial number of the
management apparatus that has previously managed the device A in the
device management table 13a at the periodic polling time of the first
management apparatus 301, the first management apparatus 301
deletes the information of the device A from the device information
management table 33b in response to a request from the management center
server 10.

[0097] Since the first management apparatus 301 cannot detect the
device A from the first sub-net 201, which is a management target,
the management center server 10 changes the state of the device A to a
"missing" state in the device management table 13a.

[0098] In the second management apparatus 302, the device A is
registered in the device information management table 33b. In the device
management table 13a of the management center server 10, the state of the
device A is changed to a "non-installed" state and the serial number of
the first management apparatus 301 is registered as the serial
number of the previous management apparatus. In the management center
server 10, at the time when the second management apparatus 302
registers the device A in the device information management table 33b,
the state of the device A is changed to an "installed" state in the
device management table 13a and the serial number of the second
management apparatus 302 is registered as the serial number of the
management apparatus in the device management table 13a.

[0099] When the management center server 10 detects the serial number of
the second management apparatus 302 from the serial number of the
management apparatus that has previously managed the device B in the
device management table 13a at the periodic polling time of the second
management apparatus 302, the second management apparatus 302
deletes the information of the device B from the device information
management table 33b in response to a request from the management center
server 10.

[0100] Since the second management apparatus 302 cannot detect the
device B from the second sub-net 202, which is a management target,
the management center server 10 changes the state of the device B to a
"missing" state in the device management table 13a.

[0102] The foregoing description of the exemplary embodiments of the
present invention has been provided for the purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise forms disclosed. Obviously, many modifications
and variations will be apparent to practitioners skilled in the art. The
embodiments were chosen and described in order to best explain the
principles of the invention and its practical applications, thereby
enabling others skilled in the art to understand the invention for
various embodiments and with the various modifications as are suited to
the particular use contemplated. It is intended that the scope of the
invention be defined by the following claims and their equivalents.